Lexus NX AZ20

2.4L turbo four — replaces the 3.5L V6 in the 2023+ RX and NX 350. Adequate power but noticeably less refined than the V6 it replaces. Timing chain stretch is the long-term concern — inspection at 80,000 miles, replacement at 120,000 miles. EGR cooler cracks have been documented on early units. Fuel injection system issues can appear around 50,000-60,000 miles. Still a young engine with limited long-term data. The turbo-four in a luxury SUV feels like a cost reduction, not an improvement.

• !! Timing Chain Stretch from 130,000 km

  The T24A-FTS timing chain stretches over time despite Toyota marketing it as maintenance-free. Tensioners compensate initially but eventually the chain develops a subtle rattle. If unaddressed, the chain can jump or break, requiring engine replacement. Inspection recommended at 80,000 miles, replacement at 120,000 miles. Expected lifespan of the engine is 160,000-180,000 miles with proper maintenance.

  Symptoms: Subtle rattling noise on cold start, check engine light (timing codes), rough idle, reduced power
  2,000–5,000 $
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• !! EGR Cooler Cracking

  Early production T24A-FTS engines show cracking of the EGR cooler, allowing coolant to leak into the combustion chamber. Produces white smoke from exhaust and progressive coolant loss. The EGR valve itself can also clog around 100,000 miles. Early 2022-2023 production units appear most affected.

  Symptoms: White smoke from exhaust, coolant level dropping with no visible external leak, sweet smell from exhaust
  1,000–2,500 $
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• !! Fuel Injection System Complications from 90,000 km

  The D-4ST dual injection system is sensitive to fuel quality and purity. Injector fouling documented around 50,000-60,000 miles. The engine requires 91 octane premium fuel — using regular fuel can cause damage and may void warranty. Regular fuel filter changes recommended.

  Symptoms: Rough idle, hesitation under acceleration, check engine light, reduced fuel economy
  500–1,500 $
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The A25A-FXS 2.5L hybrid from the Dynamic Force series is rock-solid — 250k+ km realistic. Clean EGR valve from 70k km to prevent coking. EGR cooler can crack at any mileage — watch coolant level.

• !! Oil Pan Gasket Leak (TSB) from 40,000 km

  Toyota Technical Tip T-TT-0672-21 documents oil leaks from the No. 2 oil pan on 2021-2022 TMMK-produced A25A-FXS engines. A manufacturing process issue causes the oil pan gasket to fail prematurely. Dealer repair under warranty involves oil pan reseal.

  Symptoms: Oil drip from lower engine, oil spots on ground, oil residue on oil pan surface
  200–600 $
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• ! Oil Emulsion From Short-Trip Cold Weather Use

  During short trips at freezing temperatures, moisture from blow-by gases condenses in the crankcase, producing milky emulsion on the oil cap and in the oil. TSB EG-00731T-TME (2022) addresses this. Not a head gasket leak — resolved by occasional longer drives that bring the engine to full operating temperature.

  Symptoms: Milky residue on oil cap, white deposits inside valve cover, low oil pressure warning in severe cases
  50–200 $
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• ! EGR System Clogging from 160,000 km

  The EGR system accumulates carbon deposits over time. Hybrid operation with frequent engine start-stop cycles accelerates buildup. EGR valve cleaning or replacement typically needed around 100,000 miles. Preventable with occasional sustained highway driving.

  Symptoms: Check engine light, rough idle, reduced power, increased emissions
  300–800 $
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